Circular knitting machine



Aug. 9, 1932. P. A. BENTLEY ET AL I CIRCULAR KNITTING MACHINE Filed Sept. 15, 193C 2 Sheets-Sheet l TLEY ET AL Aug. 9, 1932.

Patented Aug 9, i932 entree stares reliant FATENT PERCIVAL ARTHUR BENTLEY, CHARLES FREDERICK HANGER, AND CARLYLE HERBERT WAINWRIGHT, F LEICESTER, ENGLAND crncnnan nmr-rrne ranonmn Application filed September 15, 1930, Serial No. 482,070, and in Great Britain September 24, 19%.

This invention is for improvements inor relating to circular knitting machines and is particularly applicable to, although not limited to, circular knitting machines ofthe type that is characterized by having superposed needle cylinders within corresponding cam boxes and means to produce relative rotation and rotary reciprocation of the cylinders and cam boxes; this type of machine is exemplified in the specifications of British Letters Patent Nos. 15008/1900, 24290/1912 and 17l,t83.

An object or" the invention is to improve circular knitting machines by obviating a disadvantage sometimes present in their operation and due to the engagement of the yarn by a sinker hook at a time in the operation of the machine when such engagement is undesirable.

A. specific instance in which such a disadvantage is likely to arise is in connection with the knitting of heel and toe pouches. During this operation (which is performed upon about half the total number of needles I in the machine) the number of needles that are knitting is reduced, one by one, but as the corresponding sinkers are not also thrown out of operation, these sinkers are liable to engage the yarn by their hooks, as hereinafter more fully explained, at a period in the knitting when such engagement is not desirable.

A feature of the present inyentipn is the provision, in a circular knitting machine wherein at certain parts of the work in the knitting operation the stitch-forming tunction of a needle is automatically suspended,

of means ensuring that at such time a sinker associated with such needle shall not engage the yarn by its hook. Conveniently, such means includes a shield which is automatically brought, at the appropriate time in the knitting, into shielding relation to the sinker hook to prevent the yarn from being caught by the hook. This shield may be under the control of a device (for instance a needlecarrying slider) which is operatively connected with the needle with which the sinker is associated.

A further object of the invention is the provision in a circular knitting machine wherein at certain parts of the work (for instance at the heel portion of a sock) the needles of a group of the needles cease knitting successively, of yarn-controlling means for preventing unwanted engagement of the yarn by a sinker, comprising an arrangement wherein the point of engagement of the yarn by said means is shifted progressively (for example by the successive operation of a series of shields as hereinafter described) across the said group of needles as the needles are thrown out of action successively so as always to be in close proximity to a needle at the end of those needles of the group which are knitting, and thereby maintain the yarn out of the range of action of the hook of a sinker associated with that needle.

A convenient construction according to the invention will now be described by way of example in connection with the knitting of heels and toes of socks or like articles by rotary reciprocation on circular knitting machines of the type hereinbefore referred to, reference being made to the accompanying diagrammatic drawings in which Figure 1 is a diagrammatic representation, in plan and on an enlarged scale, of part of the plain needle cylinder with needles, sinkers and associated parts therein;

Figure 2 is an elevation of parts indicated in Figure l; and

Figures 3, 4 and 5 show, respectively, a needle, a slider,and a sinkerwith its shield, in different positions which they occupy during the operation of the machine.

in machines of the type referred to, a heel or toe is knitted on, say, half the number of needles in the needlecircle, the needles of the remaining half-circle being raised (to the position of the needles 10, 12 in Figure 2) to an idle track above the knitting track and therefore rendered inoperative as far as stitch-forming is concerned. The number of needles knitting is gradually reduced by one needle at a time until only about one-third of the half is knitting and then gradually increased to the half again. When those needles which are knitting have passed the stitch cam, the machine continues to revolve ill) in the same direction for some distance and the yarn 14, as indicated in Figure 1, lies round the outside of the stems of the needles 10, 12 which are in the idle track but of course is not knitted by them. The arrow in Figure 1 indicates the direction of rotation of the needle cylinders at this time. On the reversal of the machine this yarn is withdrawn again by a spring-operated take-up (not shown) until needles in the knitting track reach the yarn feeder 16 when knitting again takes place in the usual way.

A source of troublewhich has always eX- isted in a greater or less degree and which it is an object of the present invention to overcome is as follows When a needle has drawn a loop, the sinkers 8 move inwards and hold the yarn in their hooks, and after the last needle (i. e. the needle 18 in the drawings) which knits has drawn its loop 20 the yarn should lie freely outside the idle needles 10, 12, as shown in Figure 1, and above the sinkers on the left-hand side of those needles, but the tendency is for these sinkers to continue to take the yarn and to drag it between the idle needles 10, 12 making a wave-like formation of the yarn. When the machine reverses, the yarn must be straightened out again and pulled back through the feeder 16. To do this the take-up has to put more tension on the yarn than should be necessary and the action of the sinkers and of the take-up together have a serious effect on the yarn, often causing it to break. The finer the gauge of the machine (and consequently the greater the number of the needles and sinkers) the greater is this difficulty, because the sinkers are closer together and the yarn will not so readily lie inside the hook of one sinker and over the top of the next sinker, and also because finer and consequently weaker yarns are used.

The present invention allows the sinkers which are required for knitting to act in their usual way, but the first sinker which is not required for knitting is provided with means which definitely lifts the yarn over the top of the sinker and so causes the yarn to lie freely round the outside of the idle needles so that it may be readily withdrawn by the take-up on the reversal of the machine. This considerably reduces the dama e done to the yarn and permits higher spee s in the knitting of the heel and toe.

In the present convenient construction, those sinkers 8 which assist in forming the selvedges of the heel and toe are special sinkers which are made in two parts. One part 22 (Figures 3, 4 and 5) carries the hook 24 and the butt 26 and is in efiect, a normal sinker, that is to say, it is a thin flat blade curved in an arc of a circle, and having the hook formed at the front end of its convex margin and the butt formed on that margin near the rear end of the blade. The other part 28, which also is a thin fiat and more or less curved blade, is pivoted at 30 on the first part 22 and is arranged to take up two positions in relation to it. In the lower position (Figure 3) of the pivoted part 28, the sinker acts in the usual way, but in the upper position (Figure 5) thereof a portion 32 of the part 28 lies alongside the hook 24, completely covering or shielding it and preventing yarn entering the hook but making it slide over the top of the sinker. The part 28 of the sinker has a butt 34 which projects outwardly as a continuation of the more or less concave margin of the part 28.

The needle-carrying sliders 36 (Figure 2) of the machine which are placed in those tricks next to the special sinkers are each provided with a small piece 38 which projects from the side of the slider towards the sinker so as to be underneath the butt 34 (see Figures 4 and 5) of the part 28 of the sinker. This small piece 38 conveniently is formed by a part of the slider which is bent into a position at right angles to the general plane of the slider.

When the machine is knitting by rotary motion the sliders 36 are too low for the small pieces or projections 38 to have any-effect on the sinkers, which consequently have their hooks open and act in their usual manner, but when the sliders are raised to the idle track during the knitting of the heel or toe, their projections 38 are at such a height that each raises the pivoted part of its associated sinker to the higher position in which the sinker hook is covered or shielded.

Figures 1 and 2 are illustrative of a stage in the operation of the machine in which the needles 18, 19, 21 are knitting, while the needies 10, 12 are in the idle track to which they have previously been lifted. lVh-en the last needle which knits, i. e. the needle 18, has drawn its loop 20, the needle cylinders continue to revolve for some distance in the direction indicated by the arrow in Figure 1 and the yarn 14 is caused to lie against the outer side of the needles 10, 12. The sinker 8 on the left hand side of the needle 18 acts in usual manner to assist in the formation of the loop 20, as its hook is uncovered, the part 28 of the sinker being in the position shown in Figure 3 at this time.

But the sinker on the left hand side of the needle 10 (as well as the sinkers likewise placed in relation to the needles 12) had its hook covered when the needle 10 in an earlier stage of the operation was raised by its slider 36. As this slider 36 moved upwardly, its projection 38 engaged the part- 28 of the sinker turning it about its pivot 30, and causing its portion 32 to shield or cover the hook 24 of the sinker as shown in Figurev 5. During the continued rotation .of the needle cylinders in the direction indicated by the arrow in Figure 1, the sinker on the left hand side of the needle moves inwardly and the yarn 14 is thereby caused to slide over the upper edge of the shielding portion 32 of the part 28 as shown in Figure 4. Continued inward movement of the sinker finally causes the yarn to pass on to the top of the sinker hook 24 and at or about this time, the butt 34 on the part 28 slides from off the projection 38 on the slider 36 and the part 28 then drops to the position in which it is shown in Figure 3. The hook 24 of this particular sinker is thus prevented at this stage of the operations from engaging the yarn 14 and dragging it between the idle needles. When the sinker has moved inwardly as described, the butt 34 is clear of the projection 38 on the slider 86, so that the latter is enabled to have imparted to it a further upward movement which may take place if the slider is to transfer its needle to the top cylinder.

As shown in Figure 2, it would appear that the yarn 14 lies suficiently above the sinker to the left of the needle 10, as not to be likely to be engaged by the hook of that sinker. It should be borne in mind, however, that the sinker hook at this stage is at some distance outwardly from the yarn and that by the time the needle cylinders have turned to the stage where the sinkerhook normally performs its yarn-pulling function, the angle which the yarn 14 makes with the horizontal will be less than that shown in Figure 2 with the result that this lower position of the yarn will render the yarn very liable to be engaged by the hook of the inwardly moving sinker. Moreover, for the sake of clearness a very coarse-gauge machine has been illustrated in the drawings. On a finer gauge machine than that illustrated, the tendency for improper engagement of the yarn by the sinkers is enhanced, since the sinkers are closer together and therefore are situated closer to the low point of the yarn where the yarn merges into the loop formed by the last operative needle and sinkers.

The part 28 of each of the special sinkers has a tail portion 40 (Figures 3, 4 and 5) which extends inwardly beyond the pivot 30 of the part 28. This portion 40 which is of lesser width than the part of the sinker against which it is situated, acts to limit the movement of the part 28 about its pivot 30 by coming into engagement with the bottom of the trick in the sinker ring 42 (Figure 4) or with the upper portion of the sinker-operating cam 44 on associated part at the top of that trick (Figure 3) Although the present invention is particularly applicable in connection with the knitting of heels and toes where a relative- 1y large number of adjacent needles are thrown out of action as regards their stitchneedle in any given part of the needle cirole is thrown out of action periodically and it is desirable that the associated sinker also be rendered inoperative.

1. In a circular knitting machine, a needle, a slider for moving said needle, a hooked sinker, a shield adapted to be moved into shielding relation to the sinker hook, a butt on said shield, and a projection on said slider arranged to engage said butt.

.2. In acircular knitting machine wherein at certain parts of the work the needles of a group of needles cease knitting successively, the combination with such needles, of hooked sinkers associated with said needles, means adapted to be shifted to engage the yarn to prevent contact of the yarn with the sinker hooks, and means for shifting said first named means progressively across the said group of needles as the needls are thrown out of action successively, so as always to be in close proximity to a needle at the end of those needles of the group which are knitting, and thereby maintain the yarn out of the range of action of the hook of a sinker associated with that needle.

3. In a circular knitting machine wherein at certain parts of the work the needles of a group of needles cease knitting successively, the combination with such needles, of hooked sinkers associated with said needles,

means adapted to be shifted to engage the yarn to prevent contact of the yarn with the sinker hooks, and means movable with the needles for shifting said first named means progressively across the said group of needles as the needles are thrown out of action successively, so as always to be in close proximity to a needle at the end of those needles of the group which are knitting, and thereby maintain the yarn out of the range of action of the hook of a sinker associated with that needle.

4. In a circular knitting machine wherein at certain parts of the work the needles of a group of needles cease knitting successively, the combination with such needles, of hooked sinkers associated with said needles, a plu rality of yarn engaging elements, one located adjacent each needle, .said elements being adapted to be shifted to engage the yarn to prevent contact of the yarn with the sinker hooks,.and means for shifting successive elements progressively across the said group of needles as the needles are thrown out of action successively, so as always to be in close proximity to a needle at the end of those nee- 5. In a circular knitting machine wherein at certain parts of the work the needles of a group of needles cease knitting successively, the combination with such needles, of hooked sinkers associated with said needles, a plurality of yarn engaging'elements, one located adjacent each needle, said elements being adapted to be shifted to engage the yarn to prevent contact of the yarn with the sinker hooks, and means movable with the needles for shifting successive elements progressively across the said group of needles as the needles are thrown out of action successively, so as always to be in close proximity to a needle at the end of those needles of the group which are knitting, and thereby maintain the yarn out of the range of action of the hook of a sinker associated with that needle.

6. In a circular knitting machine wherein at certain parts of the work in the knitting operation the stitch forming function of aneedle is automatically suspended, the combination with such needle, of a hooked sinker normally cooperating therewith, means adapted to be positioned to prevent engagement of the yarn with the sinker hook, and means movable with the needle for positioning said first named means. i

7. In a circular knitting machine wherein at certain parts of the work in the knitting operation the stitch forming function of a needle is automatically suspended by moving the needle to inoperative position, the combination with such needle, of a hooked sinker normally cooperating therewith, means adapted to be positioned to prevent engagement of the yarn with the sinker hook, and means controlled by movement of the needle to inoperative position for positioning said first named means.

8. In a circular knitting machine wherein at certain parts of the work in the knitting operation the stitch forming function of a needle is automatically suspended by moving the needle to inoperative position,the combination with such needle, of a hooked sinker normally cooperating therewith, means adapted to be positioned to prevent engagement of the yarn with thesinker hook, and means carried with the needle in the movement of the latter to inoperative position for engaging said first named means to position the latter.

9. In a circular knitting machine, the combinatiom with a needle and a hooked sinker associated therewith in the knitting of yarn into a fabric, of means adapted to ensure that the yarn shall not be engaged by the hook of the sinker, at a time during which in the operation of themachine the yarn-knitting function of the needle is suspended, said means comprising a shield associated with the sinker for closing the sinker hook, and

means for moving said shield into shielding relation with said hook. I

10. In a circular knitting machine, the combination with a needle and a hooked sinker associated therewith in the knitting of yarn into a fabric, of means adapted to ensure that the yarn shall not be engaged by the hook of the sinker, at a time during which in the operation of the machine the yarnknitting function of the needle is suspended, said means comprising a shield carried by and movable with respect to the sinker for closing the sinker hook, and means for moving said shield into shielding relation with said hook.

11. In a circular knitting machine, the combination with a needle and a hooked sinker associated therewith in the knitting of yarn into a fabric, of means adapted to ensure that the yarn shall not be engaged by the hook of the sinker, at a time during which in the operation of the machine the yarnknitting function of the needle is suspended, said means comprising a shield adapted to prevent the yarn from being engaged by the hook of the sinker, a slider for moving the needle and meansoperated by said slider for moving said shield into shielding relation to the sinker hook.

12-. In a circular knitting machine, the combination with a needle and a hooked sinker associated therewith in the knitting of yarn into a fabric, of means adapted to ensure that the yarn shall not be engaged by the hook of the sinker, at a time during which in the operation of the machine the yarnknitting function of the needle is suspended, said means comprising a device pivoted upon the sinker and comprising a part adapted to shield the hook of said sinker, means to move said device about its pivot to move said part into and out of shielding relation to the sinker hook, and means to limit the movement of the said device aboutits pivot.

In testimony whereof we have signed our names to this specification.

PERCIVAL ARTHUR BENTLEY. CHARLES FREDERICK HANGER. CARLYLE HERBERT WAINWRIGHT. 

